Bow thruster for watercraft

ABSTRACT

A bow thruster includes a pump connected to an inlet opening in a bottom of the boat hull, lines extending from the pump to opposing side outlet openings in the hull below the water line, and a control (normally closed) valve for selectively controlling water flow through each line. A bow thruster control includes on-off switches for operating the inlet pump and simultaneously directing water from pump toward a selected one of the lines to steer a bow of the hull. The bow thruster can be used on V-hulls, flat-bottom hulls for river boats, pontoons, and other watercraft.

This application claims benefit under 35 U.S.C. §119(e) of provisional application Ser. No. 60/980,851, filed Oct. 18, 2007, entitled BOW THRUSTER FOR WATERCRACT.

BACKGROUND

The present invention relates to bow thrusters for watercraft, such as for boats.

Larger boats often use bow thrusters to steer their bow when traveling at slow speed, such as when docking. Known bow thrusters include a cross pipe in the boat's bow, and a reversible motor driving a propeller in the cross pipe to thrust water selectively toward one side or the other to move the bow as desired. For example, a bow thruster is particularly useful when docking in a wind. However, existing bow thrusters are expensive, difficult to install, and often have warranty and durability problems. Also, their installation is very inflexible and not easily adapted to different situations.

One style known bow thruster is fixed in the bow of V-hull boats and its cross pipe opens through holes in the boat's hull below water level. However, since the cross pipe is linear and the boat's hull is wedge-shaped for efficient travel through water, the openings in the hull's sidewalls end up being an odd elongated quasi-oval shape that is difficult to accurately cut, difficult to seal and make watertight (noting that the openings must be below water level), and hence difficult to install. Further, the installation is in a forward portion of the bow, in cramped quarters, such that installation is further made difficult. Still further, the location of the propeller and motor are a driven by a location of the side holes in the hull. This is undesirable since it may result in the motor being positioned in an undesirable place. For example, the motor (and bow thruster components) can be a trip hazard and further the entire bow thruster assembly takes up unnecessary space in the boat (keeping in mind that storage space in a boat is at a premium). Still further, the components of this style system are undesirably expensive. It is noted that this style bow thruster generally cannot be used in flat-bottom river boats since the cross pipe openings must be located below water level, and river boats are not sufficiently deep into the water.

Another known bow thruster is made to be movable between an extended stored position where the short cross tube and propeller are positioned in the water, and a recessed stored position where a short cross tube is positioned inside the hull. This storable bow thruster has problems similar to the one noted above. Specifically, the hole in the hull is oddly shaped, and hence difficult to cut and more difficult to seal and make watertight. Further, the bow thruster components are located because of a position required the bow thruster. Still further, the components of this style system tend to be very expensive, and durability and warranty can be a problem.

SUMMARY OF THE PRESENT INVENTION

In one aspect of the present invention, a bow thruster for watercraft has a hull with an inlet opening and opposing side outlet openings. The bow thruster includes a pump connected to the inlet opening in a bottom of the boat, lines extending from the pump to the opposing side outlet openings, and at least one valve for selectively controlling water flow through each line. A control switch is provided for operating the pump and simultaneously directing water from the pump through the open control valve toward a selected one of the outlet openings to steer a bow of the hull.

In another aspect of the present invention, a watercraft includes a hull having a bottom inlet opening, and opposing side outlet openings, a pump connected to the inlet opening and to the opposing side outlet openings, and at least one valve for selectively controlling water flow to the side outlet openings. A control is provided for operating the pump and simultaneously directing water from pump toward a selected one of the side outlet openings to steer a bow of the hull.

These and other aspects, objects, and features of the present invention will be understood and appreciated by those skilled in the art upon studying the following specification, claims, and appended drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a side view of a front half of a boat hull and including a bow thruster of the present invention.

FIG. 2 is a cross section taken along the line II-II in FIG. 1.

FIG. 3 is a cross section taken along the line III-III in FIG. 1

FIGS. 3A-3B are cross sections similar to FIG. 3 but of alternative boat hulls.

FIG. 4 is an enlarged view of the outlet shown in FIG. 2, and FIG. 4A is a cross section of FIG. 4.

FIG. 5 is a schematic view of the plumbing and electrical arrangements.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

A bow thruster 20 includes a pump 21 connected to an inlet opening 31 in a bottom of a boat hull by a water-supply line (such as hulls 30, 30A, or 30B), water lines (flexible or potentially rigid pipe) extending from the pump 21 to opposing side outlet openings 24 and 25 in the hull (located below the water line), and control valves 22 and 23 (normally closed valves) in the lines for selectively controlling water flow through each line. A shut off valve 33 is located in each line per US Coast Guard regulations which require a shut off on each line coming from a hole below the water line in a hull. The outlet openings 24 and 25 are located below a water line of the boat for optimal effectiveness. A bow thruster control 26 includes on-off switches 27 and 28 for operating the inlet pump 21 and simultaneously operating one of the valves 22 and 23 for directing water from pump 21 toward a selected one of the lines to steer a bow of the hull. It is contemplated that nozzles could be used in the side outlet openings 24 and 25 increase a velocity of water spray, however testing shows that water volume has a greatest effect to increase maneuverability and efficiency of operation. Advantageously, the present bow thruster can be used on V-hulls (30, FIGS. 1-3), flat-bottom hulls (30A, FIG. 3A) such as for river boats, and even on a hull formed in part by pontoons (see hull 30B with three pontoons, FIG. 3B) and other water craft. Because of its unique design, it can be used where outlets openings 24 and 25 are positioned below water level, even when the outlet openings and lines are in tight quarters. Further, it is very flexible, such that system components (including inlet and outlet openings) can be flexibly positioned in optimal locations. Still further, installation is simplified, including the ability to form and seal the inlet and outlet openings.

The present bow thruster system 20 includes five major components. Each system and component can be any size or power desired, but for most applications it is contemplated that 12V components will work well. For example, the illustrated system has the one-directional 12V pump 21, two normally closed 12V control valves 22 and 23, the two through-hull outlets (i.e. side outlet openings 24 and 25), and an electrical panel (control 26) with two on-off switches 27 and 28 operably connected to the pump 21 and valves 22 and 23 to turn the system on and off. The pump 21 is mounted in the bottom of the boat hull 30. An inlet opening 31 is drilled through the bottom and connected to the pump 21 to allow water to be sucked up by the pump 21. The pump and inlet opening can be located at optimal locations for function and service, such as under or proximate the boat console or near a front of the hull. By pushing one of the switches 27 (or 28) on the control panel 26, the pump 21 is turned on and one of the valves 22 (or 23) is opened at the same time. In a preferred formed, a red button on the switch 27 opens the starboard valve 22 and pushes a bow of the hull 30 to the port. A green button on the switch 28 opens the port valve 23 and pushes the bow to the starboard. When the respective button is released, the pump 21 shuts off and the valve (22 or 23) is closed.

The present inlet and outlet arrangements illustrated by FIGS. 4-4A greatly simplify installation of the present bow thruster system 20. A hole is drilled through the hull 30 in a direction generally perpendicular to the marginal material 39 defining the hole. A pipe outlet member 40 includes a threaded pipe stem 41 extended through the hole and having an outer end flange 43 abutting an outside surface of the hull 30. A nut 44 is run onto the threaded stem 41 and includes a second flange 45 abutting an inside surface of the hull 30, with the flanges 43 and 45 clamping against each other. A seal 46 is formed against the surfaces of the hull 30 under each flange 43 and 45 by known materials, such as silicone or a gasket material or O ring. Notably, the hole is relatively small and round such that the marginal material 39 substantially lies in and defines a plane 47, even though the hull 30 itself is three-dimensionally curved for optimal travel through water (FIG. 4). This arrangement results in a much more robust, durable and long-lasting water-tight connection, and one which is much easier to accomplish in an installation. The line 48 extending from the stem 41 is connected to the stem 41 in any convenient waterproof manner, such as to an outside of the stem.

It is noted that the electrical system of the present system 20 operates the pump 21 when either switch 27 or 28 is depressed, but each switch 27 and 28 operates only a single valve (22 or 23). It is contemplated that this can be done in a number of different ways, such as electronically by using diodes 53 to prevent “backflow” of electrical current (see FIG. 5) to prevent undesired operation of a non-selected valve, or by using switches that are connected to provide simultaneous electrical power to the motor and to the selected control valve while not powering the non-selected control valve.

It is to be understood that variations and modifications can be made on the aforementioned structure without departing from the concepts of the present invention, and further it is to be understood that such concepts are intended to be covered by the following claims unless these claims by their language expressly state otherwise. 

1. A bow thruster for watercraft having a hull with an inlet opening, and opposing side outlet openings, comprising: a pump connected to the inlet opening; lines extending from the pump to the opposing side outlet openings; at least one valve for selectively controlling water flow through each line; and a control for operating the pump and simultaneously directing water from pump toward a selected one of the outlet openings to steer a bow of the hull.
 2. The bow thruster in claim 1, wherein the control includes at least one on-off switch for controlling operation of the at least one valve.
 3. The bow thruster in claim 2, wherein the at least one switch includes a first switch with a steer-right position and a second switch with a steer-left position.
 4. The bow thruster in claim 1, wherein the at least one valve includes first and second valves each operably connected to one of the side openings.
 5. The bow thruster in claim 4, wherein the first and second valves are normally-closed control valves.
 6. The bow thruster in claim 5, wherein the valves are 12V valves.
 7. The bow thruster in claim 1, wherein the pump is a 12V DC pump.
 8. The bow thruster in claim 7, wherein the pump has an output of at least about 3.4 gal/min.
 9. A boat including a boat hull and a bow thruster as defined in claim 1, the hull being a V-bottom design.
 10. A boat including a boat hull and a bow thruster as defined in claim 1, the hull being a flat-bottom design.
 11. A boat including a boat hull and a bow thruster as defined in claim 1, the hull including pontoons with the bow thruster installed thereon.
 12. The bow thruster in claim 1, wherein the outlet openings are defined by marginal material of the hull, the outlet openings including a pipe stem extending through the marginal material and clamped to the marginal material and that extends generally perpendicular to a plane defined by the marginal material.
 13. The bow thruster in claim 12, wherein the outlet openings define generally round holes through the hull.
 14. The bow thruster in claim 1, wherein the lines are made of flexible material.
 15. A watercraft comprising: a hull having an inlet opening, and opposing side outlet openings; a pump connected to the inlet opening and to the opposing side outlet openings; at least one valve for selectively controlling water flow to the side outlet openings; and a control for operating the pump and simultaneously directing water from pump toward a selected one of the side outlet openings to steer a bow of the hull.
 16. The watercraft in claim 15, wherein the side outlet openings are defined by marginal material of the hull, the side outlet openings including a pipe stem extending through the marginal material and clamped to the marginal material and that extends generally perpendicular to a plane defined by the marginal material.
 17. The watercraft in claim 16, wherein the side outlet openings define generally round holes through the hull.
 18. The watercraft defined in claim 15, wherein the boat hull is a V-bottom design.
 19. The watercraft defined in claim 15, wherein the boat hull is a flat-bottom design. 